During breeding season, it forms cocoon in which ova are laid and fertilised. In mature worms a thick collar or girdle-like glandular thickening of body wall called clitellum is present around segments 14, 15 and 16. It is prolonged anteriorly into a fleshy lobe, the prostomium which overhangs the mouth. The first segment at anterior end is called the buccal segment or peristomium bearing the terminal crescentic mouth. The dorsal surface relatively darker and bears a dark coloured median line of dorsal blood vessel visible through semi-transparent integument. External segmentation extends internally into the body cavity. The body divided into about 100-120, small, ring-like segments, also called metameres or somites by distinct annular grooves or furrows in the body Porphyrin protects the body from injurious It is quite slimy to touch and appears brown due to the presence of porphyrin pigment in its body wall. A mature worm isĪround 15-20 cms in length and 3 to 5 mm in width. ![]() The anterior end pointed while the posterior end blunt. Unused organic food and residual soil is egested out through anus in the form of small spherical worm castings.īody elongated, rounded, narrow, bilaterally symmetrical and cylindrical. Organic matter in the soil serves as its food. during dry season in search of water.Įarthworm eats its way into the soil to excavate a burrow. Burrows are usually 20-30 cm deep but may reach 2-3 mtrs. Pheretima posthuma is the most common species.Įarthworm is nocturnal and lives in burrows in damp soil rich in humus. Thirteen of these species found in India. Largest genus is Pheretima that includes 500 species, widespread in tropical and temperate regions of the world. About 40 species of earthworms are found in India. Bahl (1926)Įarthworms has cosmopolitan distribution, with around 1800 species placed under several genera. ![]() ![]() Phylum – Annelida Class – Oligochaeta Order : Opisthopora Family – Megascolecidae Genus – Pheretima Species – posthuma.ĭetailed anatomy by Prof.
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